1. Lubricate the pedal and make certain that
it is free on the pedal shaft.
Also, see that the pedal return
spring has not lost its tension and returns the pedal to the stop in a lively
fashion.
2. The presence in the hydraulic system of any
mineral oil, kerosene,
gasoline, inferior brake fluid
or carbon tetrachloride will cause the rubber piston cups and valves
to swell and become sluggish
and inoperative. Replace all rubber parts, using only Delco factory parts.
Flush the system thoroughly with Declene or a good grade of clean denatured alcohol, then fill
and bleed with the recommended
Delco Brake Fluid until clear fluid flows from the bleeder tube. To
insure a thorough flushing,
one quart of Declene
should be bled through the system before following with brake
fluid.
3. First, check pedal clearance for proper
adjustment. Secondly,
clean top of master cylinder and remove filler cap assembly. If the pedal
is adjusted properly and if the compensating port is clear, fluid can be
seen spurting through the port
when several quick applications of the brake pedal are made. If no such action
takes place, the port is
probably plugged. Remove master cylinder, disassemble, inspect port
hole with light, check bore
and internal parts— especially
primary cup which may be swollen. Repair as outlined in "Master
Cylinder—Detailed
Service".
4. Inferior rubber cups commonly known as
"non-genuine" in many
instances swell considerably and cause corrosion, even when using
authorized brake fluid.
Replace with factory approved service parts. Flush system and refill with
the recommended Delco Brake
Fluid.